使用Puppeteer页面运行嵌套的for循环。$$eval(...)

const puppeteer = require('puppeteer');

(async () => {
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');

  // 假设页面上有一组元素，我们想要对它们进行操作
  const elements = await page.$$eval('.item', items => {
    // 嵌套 for 循环示例
    for (let i = 0; i < items.length; i++) {
      for (let j = 0; j < items[i].children.length; j++) {
        // 对每个子元素执行操作，例如修改文本内容
        items[i].children[j].textContent = `Item ${i} - Subitem ${j}`;
      }
    }
    return items;
  });

  console.log(elements);

  await browser.close();
})();

await page.waitForSelector('.item');
const elements = await page.$$eval('.item', items => {
  // 你的代码
});

const elements = await page.evaluate((selector) => {
  const items = Array.from(document.querySelectorAll(selector));
  for (let i = 0; i < items.length; i++) {
    for (let j = 0; j < items[i].children.length; j++) {
      items[i].children[j].textContent = `Item ${i} - Subitem ${j}`;
    }
  }
  return items;
}, '.item');